"The way a woman feels about tackling everyday physical activities, including exercise, may be a predictor of how much weight she will retain years after childbirth," said James Pivarnik, a professor at Michigan State University, US.

"The women who had difficulty believing they could overcome barriers that often occur in daily life or just thought they were not cut out for physical activity, overall retained 11 to 13 more pounds of pregnancy weight later on," Pivarnik said.

For the study, researchers followed 56 women during pregnancy and measured their physical activity levels, along with barriers to exercise and the ability to overcome them.

Women who considered themselves less able to take on these barriers retained more of their pregnancy weight, a follow-up six years later showed.

Top barriers identified in the study included time, motivation and childcare issues.